Expressive language delay (ELD) is a developmental disorder characterized by a delay in expressive language compared with receptive language and IQ. ELD affects a significant number of children; prevalence estimates range from .07% to 15% of the general preschool-aged population. ELD is associated with concurrent social and behavioral deviance and with long-term negative developmental outcomes. ELD is associated with elevated rates of family stress, child behavior problems and psychiatric disorder (e.g., attention deficit, oppositionality and passivity disorders). Although young ELD children do eventually acquire speech, they remain at risk for reading problems, poor academic achievement, special education placement, and continued problems in social adjustment. The purpose of this study is twofold: 1) to conduct a longitudinal study of language growth in a sample of ELD two-year-olds; and 2) to compare child behavior problems, parent-child interaction, and family stress in families of normal and ELD children